/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

#define VERBOSE_

using System;
using System.Diagnostics;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.IO;
using PdfSharp.Drawing;
using PdfSharp.Internal;

using Fixed = System.Int32;
using FWord = System.Int16;
using UFWord = System.UInt16;

namespace PdfSharp.Fonts.TrueType
{
  /// <summary>
  /// This table contains information that describes the glyphs in the font in the TrueType outline format.
  /// Information regarding the rasterizer (scaler) refers to the TrueType rasterizer. 
  /// </summary>
  internal class GlyphDataTable : TrueTypeFontTable
  {
    public const string Tag = TableTagNames.Glyf;

    public byte[] glyphTable;

    public GlyphDataTable()
      : base(null, Tag)
    {
      DirectoryEntry.Tag = TableTagNames.Glyf;
    }

    public GlyphDataTable(FontData fontData)
      : base(fontData, Tag)
    {
      DirectoryEntry.Tag = TableTagNames.Glyf;
      Read();
    }

    /// <summary>
    /// Converts the bytes in a handy representation
    /// </summary>
    public void Read()
    {
      try
      {
        // not yet needed...
      }
      catch (Exception ex)
      {
        throw ex;
      }
    }

    /// <summary>
    /// Gets the data of the specified glyph.
    /// </summary>
    public byte[] GetGlyphData(int glyph)
    {
      IndexToLocationTable loca = this.fontData.loca;
      int start = GetOffset(glyph);
      int next = GetOffset(glyph + 1);
      int count = next - start;
      byte[] bytes = new byte[count];
      Buffer.BlockCopy(this.fontData.Data, start, bytes, 0, count);
      return bytes;
    }

    /// <summary>
    /// Gets the size of the byte array that defines the glyph.
    /// </summary>
    public int GetGlyphSize(int glyph)
    {
      IndexToLocationTable loca = this.fontData.loca;
      return GetOffset(glyph + 1) - GetOffset(glyph);
    }

    /// <summary>
    /// Gets the offset of the specified glyph relative to the first byte of the font image.
    /// </summary>
    public int GetOffset(int glyph)
    {
      return DirectoryEntry.Offset + this.fontData.loca.locaTable[glyph];
    }

    /// <summary>
    /// Adds for all composite glyphs the glyphs the composite one is made of.
    /// </summary>
    public void CompleteGlyphClosure(Dictionary<int, object> glyphs)
    {
      int count = glyphs.Count;
      int[] glyphArray = new int[glyphs.Count];
      glyphs.Keys.CopyTo(glyphArray, 0);
      if (!glyphs.ContainsKey(0))
        glyphs.Add(0, null);
      for (int idx = 0; idx < count; idx++)
        AddCompositeGlyphs(glyphs, glyphArray[idx]);
    }

    /// <summary>
    /// If the specifed glyph is a composite glyph add the glyphs it is made of the the glyph table.
    /// </summary>
    void AddCompositeGlyphs(Dictionary<int, object> glyphs, int glyph)
    {
      //int start = this.fontData.loca.GetOffset(glyph);
      int start = GetOffset(glyph);
      // Has no contour?
      if (start == GetOffset(glyph + 1))
        return;
      this.fontData.Position = start;
      int numContours = this.fontData.ReadShort();
      // Is not a composite glyph?
      if (numContours >= 0)
        return;
      this.fontData.SeekOffset(8);
      for (; ; )
      {
        int flags = this.fontData.ReadUFWord();
        int cGlyph = this.fontData.ReadUFWord();
        if (!glyphs.ContainsKey(cGlyph))
          glyphs.Add(cGlyph, null);
        if ((flags & MORE_COMPONENTS) == 0)
          return;
        int offset = (flags & ARG_1_AND_2_ARE_WORDS) == 0 ? 2 : 4;
        if ((flags & WE_HAVE_A_SCALE) != 0)
          offset += 2;
        else if ((flags & WE_HAVE_AN_X_AND_Y_SCALE) != 0)
          offset += 4;
        if ((flags & WE_HAVE_A_TWO_BY_TWO) != 0)
          offset += 8;
        this.fontData.SeekOffset(offset);
      }
    }

    /// <summary>
    /// Prepares the font table to be compiled into its binary representation.
    /// </summary>
    public override void PrepareForCompilation()
    {
      base.PrepareForCompilation();

      if (DirectoryEntry.Length == 0)
        DirectoryEntry.Length = this.glyphTable.Length;
      DirectoryEntry.CheckSum = CalcChecksum(this.glyphTable);
    }

    /// <summary>
    /// Converts the font into its binary representation.
    /// </summary>
    public override void Write(TrueTypeFontWriter writer)
    {
      writer.Write(this.glyphTable, 0, DirectoryEntry.PaddedLength);
    }

    // Constants from OpenType spec.
    const int ARG_1_AND_2_ARE_WORDS = 1;
    const int WE_HAVE_A_SCALE = 8;
    const int MORE_COMPONENTS = 32;
    const int WE_HAVE_AN_X_AND_Y_SCALE = 64;
    const int WE_HAVE_A_TWO_BY_TWO = 128;
  }
}
